|Max. width||137 m (449 ft)|
|Max. depth||64 m (210 ft)|
|Surface elevation||0 m (0 ft)|
Lake Voulismeni (Greek: Λίμνη Βουλισμένη, Límni Voulisméni) is a former sweetwater small lake, later connected to the sea, located at the centre of the town of Agios Nikolaos on the Greek island of Crete. It has a circular shape of a diameter of 137 m and depth 48.8m. The locals refer to it as simply "the lake". The lake is connected to the harbour of the town by a channel dug by the French army in 1907. A panoramic view of the lake can be seen from a small park situated above it.
According to legend, the goddess Athena bathed in it. Every year at midnight turning to Orthodox Christian Easter day, the majority of the population of the town gathers around the lake to celebrate with fireworks, and firecrackers thrown by the people attending that highlight event.
The rocks at the lake are limestone breccias, the result of undersea landslides coming down from the mountains to the north-west of the town.
A normal fault which cuts right through the town in a roughly NNE to SSW direction passes directly through the north-western side of the lake, the cliff at the lake is the scarp slope of this fault. Elsewhere in the town the fault was later buried by subsequent underwater landslides. An underground stream that was cut by this fault created a solution sinkhole and a small cave following the disappearance of the overlying sea during the Messinian Salinity Crisis. After only a few hundred thousand years the small cave, dissolved out of the unstable and structurally weak breccia, collapsed creating a deep hole. The destabilised breccia at the top of this hole subsided into the hole creating a deep funnel-shaped sinkhole which was subsequently filled with freshwater by the still running spring. The creation of the Mediterranean Sea during the Zanclean Flood left a deep, spring-fed, freshwater lake that overflowed via a small stream into the nearby sea.
In 1852 Captain Thomas Spratt surveyed eastern Crete on behalf of the Royal Navy and recorded the lake as being '...a small circular pool of brackish water' and '....having a small stream opening out of it into the sea', clear evidence that the spring was still flowing at that time. He also measured the depth of the lake as 210 feet (64m) and it is this figure that is used in almost all publications and writings about the lake today. In September 2000 the geology department of the University of Athens conducted a detailed underwater survey of the lake, they found its maximum depth to be only 48.8m. The results of this survey appear not to have been widely publicised outside the geological community.
On 12 October 1856 a massive earthquake occurred in the sea off Crete with an epicentre only 40km from the lake. Although its magnitude was not recorded it was listed as grade XI on the Modified Mercalli Intensity Scale, one grade down from the maximum possible. This earthquake was most likely responsible for the blocking or diversion of the freshwater spring leading to the later stagnation of the lake and the collapse of the western corner of the lake which reduced the lake depth from the 64m measured by Thomas Spratt to the 48.8m today.
By the end of the 19th Century the lake was stagnant, it was known locally as Vromolimni, 'the stinky lake'. The digging of the channel to the sea in order that the more dense seawater could flush away the stagnant water and the smell most likely happened in 1907 when the French Army were stationed in the town as guarantors of Cretan independence prior to its union with Greece.
A local urban myth is that the lake is bottomless and the crater of an extinct volcano. That notion is most likely based on its impressively high depth compared to its width (48.8m depth and only 134m width) or/and on locals noticing disturbances at the surface or also the level of the water during the 1956 Amorgos earthquake (which was wrongly attributed to an eruption of Santorini). Because of the latter, many assume a possible (and incorrect) geological relation of the two locations.
The complete absence of igneous rocks anywhere near the lake precludes its being a volcano, the supposed connection with Santorini can also be dismissed for the same reason.
- "Municipality of Aghios Nikolaos – On Agios Nikolaos". Archived from the original on 14 January 2007. Retrieved 5 May 2007.
- "CRETEgazette – Coming Events in Crete". Retrieved 5 May 2007.
- "Photo from Easter at explorecrete.com". Retrieved 5 May 2007.
- Spratt T.A.B. John Van Horst, 1865, p. 144.
- "NOAA Significant Earthquake Database (search terms 1815-1900, Southern Europe, Greece, Crete)". Retrieved 9 October 2019.
- "Stigmes Cretan Magazine (also in print)". Retrieved 5 May 2007.